Valve-gear for engines.



"um 673,076. Patented Apr. 3o, 19m.

FAwELL.

VALVE GEABFOR ENGINES.

(Application led Jan. 5. 1900-1 3 Sheets-Shank l.

(lolodel.)

um. wm

www...

NSW

` Atty.

n ESSES: mi 7751,@

jm. 673,076. Patentd Apr. 3o, lem.

.1. FAwELL. VALVE GEAR FOR ENGINES.

, (Application med un. 5, i90-o.)

(Ng Model.) 4 3 Sheets-Sheet 2.

wrrnss'sss: mvznfon 1N: mms Ktm cu.. mmurmq.. Mumba, n, c.

im. 673,076. Patented Apr. 3o, lem.

J. FAwELL. v-ALvE GEAR Fon exclues.

(Application 'Ied Jxm.V 5. 19004 (No Rodel.) l 3 Sheets-Sheet 3.

rn' la.

ITNESSES: 4 v B.alll-Ve'lI-TQI UNITED STATES PATENT OEEICE.

JOSEPH FAWELL, OF PITTSBURG, PENNSYLVANIA.

VALVE-GEAR FOR ENGINES.

SPECIFICATION forming part of 'Letters Patent No. 673,076, dated .April30, 1901.

Application tiled January 5, 1900. Serial No. 490. l@I model.)

To all whom it muy concern:

Be it known that I, JOSEPH FAWELL, a citi- Zen of the UnitedStates,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented or discovered certain new and usefulImprovements in Valve-Gear for Steam-Engines, of which improvements thefollowing is a specification.

The invention described herein relates to certain improvements in thereversing mechanism for engines for blooming-mills; and has for itsobject a construction whereby the valve-operating mechanism- 02. e., thelinks, &c. -of the main engine can be rapidly shifted in eitherdirection without any appreciable shock to the reversing mechanism orthe parts shifted thereby.

The invention is hereinafter more fully described and claimed.

In the accompanying drawings, forming a part of this specification,Figure 1 is a view, partly in section and partly in elevation, showingthe reversing mechanism and lthe parts of the main engine shiftedthereby. Fig. 2 is a sectional view, on an enlarged scale, of thereversing cylinder and piston and its controlling-valve mechanism; andFig. 3 is a transverse section, the plane of section being indicated bythe line III III, Fig. 2.

In the practice of my invention the stem 1 of the valve of the mainengine is connected to arm 2 of a rocker-shaft, the other arm 3 of saidshaft being connected to a rod 4, the opposite end of which is connectedto a block 5. The rod 4 and block 5 are supported with a freedom ofback-and-forth movement by a rocker-arm 3a. The sides of the link 6 arearranged in guide-grooves in the sides of the block 5 and areprovidedvnear their ends with trunnions 7 for the reception of the endsof rods 8, extending from the eccentric-straps 9. Trunnions 10 areformed on the sides of the link, intermediate of the trunnions 7, forengagement with the upper ends of lifting-bars l1, which have theirlower ends connected to an arm 12 on the rock-shaft 13. The link 6,which is counterbalanced by a weighted arm 14, also secured to the shaft13, is raised and lowered to eect a reversal of the main engine by amotor connectedtto an arm 15, having its inner end secured to therock-shaft 13. The motor for shifting the link consists of ahuid-pressure cylinder 16 and a piston 17, which is preferably connectedto arm by means of asliding block 18, connected to the piston-rod andalso to one end of a bar 19, having its opposite end connected to thearm 15.

In order to provide for an adjustment of the traversel of the valve ofthe main engine in accordance with the work being done, the arm 15 isprovided at a series of two or more points with suitable meansA forattaching the' end of the bar 19 thereto. The means employed forconnecting the bar to the arm may be of any suitable construction-as,for example, the bar may be formed with an eye through which bolts 2O20a, &c., can pass. These bolts or other attaching means are arranged onthe armin an arc of acircle Whose center coincides with the point ofconnection of the bar 19 with the sliding block 18. By shifting theconnection of the bar with the arm from the point or bolt 20 to thepoint or bolt 2Ob the less will be the range of vertical movement of thelink with a constant stroke of the piston.

As shown in Fig. 2, the valve-chest 21 is connected to the ends of thecylinder by inlet-ports 22 22aand exhaust-ports 23 23a, the

flow of steam through said ports being controlled by a valve 24, whichis preferably made in two sections connected by a stem 25, which has oneend connected to a hand-lever `26 or other shifting mechanism. 4 It willbe observed that the exhaust-ports 23 23a are so located as to be closedby the piston 17 be- -fore it reaches the ends of its movement, so

that a quantity of steam will be inclosed between the ends of thecylinder and the piston, forming a cushion for the latter. In order topermit the piston to complete its stroke, the exhaust-ports 23 23a areconnected by pipes or passages 27 27a to auxiliary exhaustports 28 28a,located at the ends of the cylinder, thereby providing for the escape ofsteam from the cylinder after the ports 23 or 23a have been closed bythe piston. The speed of the piston during the final portions of itsstroke is controlled by means of valves 29 29a, located in the pipes orpassages 27 27a. The exhaust-ports are connected to the outlet-passages30 30aM by recesses 31 31a in the valve, said recesses beingso locatedasto connect the ports and passages at one end of the IOO cylinder onlywhen the valve is in position to permit the flow of steam through theinletport at the opposite end of the cylinder. It will be observed thatthe pipes or passages 27 27a connect with the exhaust-ports 23 23L atpoints intermediate of the ends of the latter, so that when theexhaust-ports are closed by the valve 24 no steam can escape from thecylinder.

The valve and piston of the shifting cylinder and the valve mechanism ofthe main engine operated by the shifting cylinder and piston are inintermediate or non-operative positions. lf the lever 26 be shifted tothe left, the steam-inlet port 22*L will be opened and the exhaust-port23 will be connected to the outlet-passage 30. As the piston moves tothe left it will cover the exhaust-port 23, so that the exhaust-steammust pass through the auxiliary port 2S, passage 27, and port 23 to theoutlet. By partially closing the passage 27 the final rate of movement of the piston can be reduced to any desired degree. The rate of movementIof the piston from the time it starts until caught by the cushion can beregulated by means of an auxiliary valve 32 in the steam-supply pipe 33or by valves 34 in the exhaust pipes or passages 30 30a, or by both. Byadjusting the valves in the exhaustpipes the back pressure on the pistoncan be increased or diminished, thereby effecting a corresponding changein the speed of the piston.

It is characteristic of my improvements that the speed of the piston ofthe shifting cylinder for any portions of its stroke can be regulatedindependent of the reversing-valve 24 and that an eiective butgradually-diminishing cushion is automatically formed at the ends of thecylinder by the piston itself.

I claim herein as my invention- 1. As a means of reversing asteam-engine, the combination of a piston connected to thevalve-operating mechanism of the main engine, a cylinder provided withindependent inlet and exhaust ports, the exhaust-ports being so locatedas to be closed by the piston in its traverse and having at its endsValved auxiliary exhaust-ports, a main valve and auxiliary valvescontrollingihe inlet and exhaust ports, substantially as set forth.

2. As a means for reversing a steam-engine, the combination of a piston,a cylinder provided with independent inlet and exhaust ports, the latterbeing so located as to be closed by the piston in its traverse andhaving at its ends auxiliary exhaust-ports con-v nected to the mainexhaustports, a main valve and auxiliary valves controlling the inletand exhaust ports, substantially as set forth.

3. As a means for reversing a steam-engine, the combination of a piston,a cylinder provided with independent inlet and exhaust ports, the latterbeing so located as to be covered by the piston in its traverse, andhaving auxiliary exhaust-ports having valved connections to the mainexhaust-ports, a main valve controlling the inlet and exhaust ports, andauxiliary valves controlling the outflow of steam, substantially as setforth.

4. As a means for reversing a steam-engine, the combination of areversing-Valve mechanism, a rock-shaft connected thereto, an armsecured to said shaft, a cylinder and piston, abarhaving one endconnected to said piston and means for detachably connecting theopposite end of the bar to one of a series of points of attachment onthe arm, substantially as set forth.

In testimony whereof I have hereunto set my hand.

JOSEPH FAWELL. Vitnesses:

DARWIN S. WoLoo'rT, F. E. GAITHER.

